Gun-sight.



PATENTED JULY 30, 1907.

w. J. HAWKINS.

' GUN SIGHT.

A-IPLIOATION rmzn 1120.1. 1006.

2 SHEETS-SHEET 1.

PATEN'I'ED JULY 30, 1907.

W. J. HAWKINS.

GUN SIGHT.

APPLICATION nun no.7. 1900.

2 snnn'rs anzm 2.

aswenloz rwrnnrr ornrcn.

\VILFOl'tD .l. l.[AWl IlNS, OF THE UNITED S'JATES ARMY.

Specification of Letters Patent.

Patented July so, 1907.

Application filed December 7,190f. Serial No. 346,808.

- To all whom it may concern:

Be it known that \Vrtronn .T. llAt'Kl'NH, a lieutenant in the army of the United States, and a citizen of the United States, residing at Springfield, in the county of Ilampden and State of Massachusetts, has invented certain new and useful Improvements in Gun-Sights, of which the. following is a specification.

This invention relates to new and useful improvements in gun sights and it particularly pertains to a novel sight for shoulder arms.

The invention specifically comprises a gun sight comprising a fixed base, a movable base, a sight leaf carried upon said movable base and a slide block movable longitudinally of said sight leaf. These elements constitute the rear sight and are employed in connection'with a novel embodiment. of front sight.

The invention aims as a further object to provide novel means for adjusting the sight leaf by means of a windage scale to compensate the flight of the bullet inaccordance with the direction and strength of the wind.

The invention aims as a further object to provide a slide block embodying means for locking the same against play in any position upon the sight leaf which said slide block may be adjustably moved. The invention aims as a further object to provide a sight. in which is embodied an apertured sight disk or plate having an adjustment independent of the slide block, in order that the sight disk or plate may be set at any desired adjustment without moving the slide block. Consequently a marked advantage is at- -tained over the prior art wherein the slide block and sight plate are moved synclu'onously when it is desired to adjust the latter so as to bring a selected opening into the line of vision.

A still further object of the invention is to provide in connection with the means for moving the slide block vertically of the sight leaf, novel means for indicating the degree of such movement and from which sighting calculations may be made. In specific terms the means for moving the slide block comprises an elevating screw having its threads at a selected pitch whereby the slide block is moved by one complete or fractional revolution of said screw, a corresponding distance which is a known and determinate fraction of the sight radius.

The invention aims finally to provide a sighting mechanism in which the mechanism for adjusting the bases with. relation to the windage scales is completely housed and consequently protected from dust and rain.

The detailed construction will appear in the course of the following description in which reference is had to the accompanying drawings forming a part of this specification, like characters of reference designating similar parts throughout the several views, wherein, I Figure 1 is a front elevation of ai gun sight constructed in accordance with my invention. Fig. 2 a side elevation thereof. base. Fig. '1 is a section on the line -1-4 of Fig. 2. Figs. 5 and G are respectively front and rear plan views of elements of the slide block to be hereinafter spccific ally referred to. Fig. 7 is a fragmentary side elevation of the slide block in position upon the sight leaf. Fig. 8 is a horizontal section of the sight disk and its associated parts which are carried by the slide block. Fig. 9 is a top plan view of means for engaging the slide block with its adjusting mechanism. Fig. 10 is a front elevation of the slide block. Fig. 11 represents the drift slide plate which nioves along the sight; leaf in front and top elevation. Fig. 12 is a top plan view of the sight leaf. Fig. 13 is a section on the line 13-l3 of Fig. 4, Figs. 14:, 15 and 16 are respectively rear, front and side elevations of the front sight, and Figs. 17 and 18 are diagrams which will be specifically referred to hereinafter in describing the mode of use'ef certain elements.

Referring specifically to the accompanying drawings the numeral 1 designates the barrel of a gun which adjacent to its stock is provided with a fixed base 2 in the form of a sleeve surrounding said barrel, and upon which the elements of the sight are moimted. The base 2 is provided at a point off-center adjacent. its forward end with an enlarged vertical post 3 which serves as a pivot for the movable base 4. The base 2 adjacent its forward end is formed with a slightly curved transverse slot 5 through which projects a depending post 6 carried by the base 4. The post 6 is provided with a threaded aperture in its lower end through which is received, an adjusting screw 7 transversely journaied in the side walls of the base 2, the screw 7 carrying at one end thereof a knurled finger piece 8 and being surrounded within the base 2 by an expansive coil spring 9 for taking up the back lash or play of the screw 7 in the fixed base 2 and of the post 6 with relation to said screw. As shown in Fig. 13 the screw 7 is capableof a limited play by reason of the openings 10 in the base 2 through which said screw projects, being of slightly en largcd diameter. This play is necessary in order to compensate for the amplitude of the pivotal motion of said base 4 and the said post 6 carried thereby. It will be apparent that the base 2 scrvcs as a housing for the traversing mechanism to protect the same from dust and rain. i

Fig. 3 is a top plan view of a fixed The fixed base 2 is provided at each end thereof with- I of which the marksman sets his sight to correct for the strength and directionofthe wind.

i 3: i. o

In the following illustrations refcrencc is had to the chart shown in Fig. l7 in whi h 0 represents a point on the line of fire towards which the various winds blow and which for the purposes of illustration is centrally located in the circle. The Roman numerals I to Xll reprcsrnt eqni-distant points in alinement with O by which the direction of the wind is determined. To illustrate the manner of using the scales If and 12, we will refer to the scale 1]. on the rear end of the base 4, which is arbitrarily so graduated that each smallest division or calibration corrects for what is known in the parlance of marksman as a two mile an hour, three oclock wind, that is wind which blows from the right at. a right angle to the line of fire with a. velocity of twomiles an hour. As shown in Fig. 17 such a wind will blow from III to 0. Now, with snclra basis of calculation in mind it will be readily apparent that a four mile an hour one oclock wind has the same (leflect ing power as a two mile an hour three oclock wind, the last; wind being along the line I0 and forming an angle of 00 with the line 111 O. This will be understood since the cosine of G0 is one half. If in practice, the marksman faces a. two milean hour one oelock wind he calculates therefor by multiplying I-O representing the deflecting strength of a two mile an hour 1 oclock wind by the cosine of the angle I 0 III or one half. ty such multiplication we find that; the deflecting power of a two mile an hour one oclock wind is equal to {r of OIII which represents the deflecting power of a two mile an hour three oclock wind, or O- P. Other calculations with different angles from the line O--Ill as a leg are made accordingly. Therefore for a two mile an hour one o'clock wind the movable base is accordingly set half a space or division with relation to the proper caliln'ation.

To the rear of the base t a sight leaf 13 of open rectangular shape is pivoted. The sight leaf ]3 has its vertical sides marked with indexed calibrations 14 which indicate the respective sight settings for the various ranges under normal conditions of atmosphere. The base 4 is recessed to receive the sight leaf therein in its folded position and said sight. leaf is held in either its folded or raised position by means of a. strong leaf spring 15 which bears against that portion of the sight leaf embodied in the pivot joint 10.

In Fig. 10 is shown a preferred form of slide block employed in cmmection with the sight leaf 13. This slide block is designated by the numeral 17 and is provided at each side thereof with vertical ways 18 which receive the vertical sides 14 of the sight leaf 13, and are of great or width than said sides so as to have play with relation thereto for a purpose to be described. The slide block 17 is closed by an ornamental cap plate 1.) illustrated in Fig. 5 which. is rigidly fixed thereto and in its lower portion is provided with a central opcning 20 which rcgistcrs with a. semi-circular rcccss I!) in the lower portion of the slide block 17. The cap platc l!) is secured to the slide block by nuts or screws passing through corresponding openings 22 in said cap plat and slide block. The means for vcrtically adjusting the slide block to any desired position on the sight leaf comprises a vertical screw 23 journnlcd in the upper and lowcr portions of the Sight lcaf and in parallelism with the pcr wndicular axis thereof. The screw 22 at its upper end carries a notched thumb nut; 24 provided with marked reading adjacent each notch to indicate the degree of rotation or partial rotation of the screw 23. There are preferably ten of such readings which divide a single revolution of the screw 23into ten equal parts. The sight leaf 13 is provided with an index line 25 which points to the cali' brations on the nut 24.

The screw 23 has its threads so pitched that cach rotation thereof moves the slide block 17 a prcdcten mined and known distance upon the sight leaf ]3. Hence by referring to the scale on the nut 24 the marksman knows as he relates the screw 23 to just what degree the slide block 17 is moved upon said sight leaf. The advantage of this arrangement will be apparent from the following illustrations based on the diagram shown in Fig. 18. In these illustrations it is assumed for the sake of example that the threads on the screw 23 are so pitched that one revolution of said screw moves the slide block vertically by an amount equal to of the sight radius. In the following equations B 0 represents the sight radius, 13 A the sight setting, C I) the range and D E the distance subtended at the target by the sight setting. 'From the principle of similar triangles we have A ll B C 1: E I) D C. With the pitch of the thread as above stated, it will be evident that the movement of the slide block due to one revolution of the elevating screw will at the target correspond to a vertical movement equal to of the range or C D, on account of the principle ofsimilar triangles. With the fraction which is chosen simply for convenience of illustration, the subtended vertical movement at the target at a range of 1,000 yards (equal to 36,000 inches) by one revolution of the adjusting screw is 36,000 or 40 inches. lleucc each division on the nut 24 at a range of 1,000 yards represents a subtended vertical movement at the target of 4O inches or 4 inches. Therefore at a range of 500 yards one revolution of the elevating screw corresponds to fl xlt) or 20 inches which is subtended at. the target and each division of the thumb nut corresponds to 5x20 inches or 2 inches, etc. From these illustrations, the principle 01' the elevating screw 23 will be apparent, i. c. that its pitch is so selected as to cause the slide block to be raised or lowered by one revolution of the elevating screw by an amount equal to some convenient fraction of the sight radius 13 The slide block 17 is provided with a horizontal rcccss 26 extending from one side thereof to a point near the center and having received therein a sliding mcmbcr 27. The latter is in turn recessed as at. 28 to intcrfit the side of the sight leaf l3 and at. its inner end is formed with a semi-circular threaded rcccss 20 which bears against and meshes with the threads of the screw 23.

For the purpose of maintaining the member 27 in cugagcmcnt with the screw 23, an expansive coil spring 30 is scati-(l in said member and bears against. a projecling web 30" provided in'the recess 20 adjacent to its outer end. The member 27 may be moved mauually to disengage the same from the screw 23 and is accordingly formed with a milled or knurled end 1H. in Fig. 0 the view of said member is on an enlarged scalc.

'lln sight leaf ]3 has the inner edges of its side bars inclincd in parallelism as at 32 so as to afford an under-cut. recess 33 having its axis extending at; an angle a I L;

(ill

to the perpendicular axis of said sight leai. The slide block 17 in its vertical adjustable movenn-nt follows the axis of the under-cut recess 33. This is possible on account of the play above referred to between the recess 18 and the side bars of said sight leaf. For the purpose of guiding the slide block in the undercut recess 33, a slide plate 34 to be called the drift slide plate is provided. The recess 33 is of dovetail shape and the plate 3=l conforimibly iils therein. The plate 3-1 is illustrated in detail in Fig. l l and is formed with openings 35 through which pass fastening means to screw said plate to the cap plate l9 and with an enlarged opening 36 which registers with the opening 20 and the recess 2]. 'l.hrongh the uppermost of the openings 35 of said cap plate, a pin 37 is projected. This pin 37, while serving the incidental functimi of a fastening means for the drift slide plate also serves to carry at its front end a sight disk 38. The disk 38 is formed with openings 35) of various sizes and shapes in accordance with the character of the mark, the personal preference ,of the nuirksman and the eonditions of light. In adjusting the disk 38 so as to bring a desired opening 39 in registry with the openings 36, 20 and 2!, said disk manually rotated, the rotation thereof being facilitated by the presence 01' a knurled edge ill. For the purpose of holding the disk 40 at any position to which it may he set, ratchet projections ll are provided centrally upon the rear face thereof and engage in correspoiuling' notches 12 provided upon the. front face of the slide block cap 19 as is clearly shown in Figs. 5 and 6. The projections 41 are held in engagement with the notches 42 by means of a spring -13 surrounding the pin 37 and interposed between the rear face of the slide plate 34 and the enlarged head if of said pin. In Fig. 8 I have illustrated the disposition of the various elements, the cap plate iii being next to the sight disk 38 and the plate 34 being interposed between said cap plate and the slide block 17, the. latter being omitted from Fig. 8. it will of course he iuidtn'stood that the cap plate 1.) is of a size and shape to completely cover all of the. openings 39 in the plate 38 except the opening which is aimed with the openings 36 and 20 and the recess 31.

in Figs. 14, 15 and lb I have illustrated a novel embodiment of front sight comprising a. sleeve 15 fixed to the barrel and having a rearwardly and downwardly inclined upper surface 46 having a central longitudinal dovetail groove 47 therein. Slidably mounted in the groove i7 is a block {i8 having a dovetailed projection on its inclined lower face which interiils said curve. The block is is formed in its upper face with a transverse dovetailed groove 50 within which is received a transverse. dovetailed projection 5] carried upon the sight 5?. It will hence be observed that a vertical and lateral adjustment of the sight 5'. is permissible through the connections dcseribed between the same and block 18 and between the block i8 and the fixed base 15.

The manner of use will be readily apparent. The front and rear windagc scales ]2 and ll. are arbitrarily calibrated in ord r that the base i may be set to correspond to the velocity and direction of the wind by using one or the other of said scales. 'lhebaek apertures 3f) which the marksman uses depends upon the personal preference of the marksman, the clearness of the' mark and the atmosphere. When the base 4 has been set with relation to the proper windage scale 1] or 12, by means of the. threaded shaft 7, the slide block 17 is moved to raise the sight disk to the proper elevation. The scale on the nut 24 aids materially in this adjustment. When it is desired to raise the slide block quickly without the use of the screw, the mem her 27 is pushed inwardly against the tension of the spring 30 and the re. 29 is disengaged from said screw. The slide block may then he moved manually in either direction upon the sight leaf. The under-cnt groove 33 is extended to the left since in shoulder arms the twist of the rifle is to the right and hence the drift; of the bullet is to the right of the line of fire. Hence the drift groove 33 is inclined to the left so as to automatically correct for a right hand drift. In those cases where the twist of the rifle is to the left, the drift groove 33 will of course extend to the right as will be readily understood.

While the elements herein shown and described are well adapted to serve the functions set forth, it is obvious that various minor changes may be made in the proportions, shape and arrangement of the several parts without departing from the spirit and scope of the invention as defined in the appended claims.

Having fully described my invention I claim:

1. A device of the type set forth comprising a fixed base including a tubular portion adapted to surround the barrel of a gun. a movable base pivoted thereto, a transverse threaded shaft having lateral play in said fixed base, said fixed base having in its upper surface a transverse curved slot. at post dependin; from said movable base passing through said 5101; and having a threaded opening surrounding said shaft in engaged relation and sighting meehan isms carried by said movable base.

2. A device of the type set forth eom u-ising a fixed base inclndin a tubular portion adapted to surround the barrel of a gun, a movable base pivoted thereto, a transverse threaded shaft. having lateral play in said fixed base. said fixed base having in its upper surface a transverse curved slot. a pest depending from said movable base passing through said slot and having a threaded opening surroundin; said shaft in engaged relation, a sight leaf pivolallv mounted at one end of said movable base and a leaf spring carried by said movable member and arranged to hold said sight leaf.

3. A device of the type set forth comprising a fixed base. a movable base pivoted thereto, a transverse threaded shaft having lateral play in said fixed base. said fixed base having in its upper surface a transverse curved slot, :1 post depending from said movable base passing through said slot and having a ibreadedopening surrounding said shaft in engaged relation illlll lj {l|flll 4' mechanism carried by said movable base.

in testimony whereof I ailix my signature in presence of two witnesses.

\Yl lil 'Ult l) .T. HAWKINS. 

